This type of apparatus commonly involves large force and shock transmissions from a hammer to a striker pin as a means of breaking rocks. The forces involved in such an action can place high stresses on the entire apparatus including the machinery supporting same.
In order to miniraise the damage such forces can cause to the apparatus modifications have been proposed with a view to absorbing structurally damaging shock as it occurs in this type of apparatus.
In Australian Patent No. 585274 there is disclosed rock-breaking apparatus, which apparatus includes a guide column within which a weight falls under gravity to strike a tool. A piece of shock-absorbing material is located at or near the base of said column such that it enables force to be transmitted from said weight to the tool, while miniraising the effect of the impact of said weight on other parts of the apparatus.
Whilst such an arrangement miniraises the effect of the impact of the weight on the apparatus, rock-breaking apparatus of the type disclosed in Australian Patent No. 585274 is often used to break very hard types of rock. Often, this means that several blows will be required to cause a single fracture in the rock. On each occasion where the rock does not break, there occurs a recoil through the tool to the apparatus, causing stress in the entire apparatus and in the carrier for the apparatus.